• DOI:10.1086/509882
• Corpus ID: 18852560

On the Nature of the Unique Hα-emitting T Dwarf 2MASS J12373919+6526148

@article{Liebert2007OnTN,
  title={On the Nature of the Unique H$\alpha$-emitting T Dwarf 2MASS J12373919+6526148},
  author={James William Liebert and Adam J. Burgasser},
  journal={The Astrophysical Journal},
  year={2007},
  volume={655},
  pages={522-527}
}

• J. Liebert, A. Burgasser
• Published 28 September 2006
• Geology, Physics
• The Astrophysical Journal

We explore and discount the hypothesis that the strong, continual H?-emitting T dwarf 2MASS J12373919+6526148 can be explained as a young, low-gravity, very low mass brown dwarf. The source is already known to have a marginally fainter absolute magnitude than similar T dwarfs with trigonometric parallax measurements and has a tangential velocity consistent with old disk kinematics. Applying the technique of Burgasser et al. on new near-infrared spectroscopy for this source, estimates of its Teff, log g, and metallicity ([M/H]) are obtained. 2M 1237+6526 has a Teff ? 800-850 K. If [M/H] is solar, log g is as high as ~5.5 (cgs) and this source is older than 10 Gyr. We find a more plausible scenario to be a modestly subsolar metallicity ([M/H] = -0.2) and moderate log g ~ 5.0, implying an age older than 2 Gyr and a mass greater than 0.035 M?. The alternative explanation of the unique emission of this source, involving an interacting, close, double degenerate system, should be investigated further. Indeed, there is some evidence of a Teff < 500 K companion to 2M 1237+6526 on the basis of a possible Spitzer IRAC [3.6]-[4.5] color excess. This excess may, however, be caused by a subsolar metallicity.